Association of an inhibitor with deficiency of plasma-clearing activity

¹ Coagulation Research Laboratory, Department of Surgery, Presbyterian- St. Luke's Hospital, Affiliated With the College of Medicine, University of Illinois, Chicago, Illinois

Citrated human plasmas obtained from patients without prior injection of heparin were studied for their lipemia-clearing activity (LCA) in the presence of partially purified human clearing-factor preparations. LCA was determined by measuring the change in optical density of a clearing system consisting of the plasma to be studied and a standard fat emulsion. Under these conditions, reduced or totally lacking plasma-clearing activity, presumably due to plasma-cofactor deficiency, could be largely and, often, completely restored by any one of the following procedures: a) addition to plasma of Na-citrate, Na-oxalate or Na-Versenate; b) addition to it of heparin, manuronate, polyethylene sulfonate or G-31150/III; c) addition of certain sulfhydryl inhibitors; d) adsorption of plasma with barium sulfate; and e) its preincubation with purified human plasmin. The results indicate that excessive inhibitor levels in plasma rather than a lack of cofactor may be responsible for clearing deficiency.